In recent years, 3D images attract attention. A generally used method for viewing a 3D image is such that a person wears glasses that open the left eye shutter during displaying of one of images of two viewpoints and that open the right eye shutter during displaying of the other of the images, and the person views the images of the two viewpoints which are displayed alternately (hereinafter referred to as “method using glasses”).
However, with such method using glasses, it is necessary for a viewer to purchase the glasses in addition to a 3D image display device, which reduces the appetite for purchase. Moreover, the viewer has to wear glasses during viewing, which is troublesome. Therefore, the demand for a viewing method for viewing 3D images without wearing glasses (hereinafter referred to as “method without glasses”).
In the method without glasses, images of three or more viewpoints are displayed in such a manner that the viewable angle is different for each viewpoint, and when the viewer sees images of two viewpoints with the right and left eyes, the viewer can see a 3D image without wearing glasses.
The following method has been made as a display method of 3D image according to the method without glasses. In this method, a color image and a depth image of a predetermined viewpoint are obtained, and using the color image and the depth image, color images of multiple viewpoints which are display viewpoints including viewpoints other than the predetermined viewpoint are generated and displayed. It should be noted that “multiple viewpoints” mean three or more viewpoints.
As a method for encoding color images of multiple viewpoints and a depth image, a method for separately encoding the color images and the depth image has been suggested (for example, see Patent Document 1).